BORNEAN ORANGUTAN POPULATION HALVED IN THE LAST TWO DECADES

“THE LARGEST NUMBER OF ORANGUTANS WERE LOST FROM AREAS THAT REMAINED FORESTED”

Logging, hunting and the demand for palm oil have led to the estimated loss of nearly 150,000 Bornean orangutans – almost half of the total population – since 1999, a huge international study has found. The comprehensive study combined observations from 36,555 orangutan nests collected by 38 different institutions. It estimated that a total of 148,500 animals were lost between 1999 to 2015.

“The decline in population density was most severe in areas that were deforested or transformed for industrial agriculture, as orangutans struggle to live outside forest areas,” said Maria Voigt of the Max Planck Institute, Germany, who led the research. “Worryingly, however, the largest number of orangutans were lost from areas that remained forested during the study period. This implies a large role of killing.”

Based on predicted future reductions in forest cover and the assumption that orangutans ultimately cannot survive outside forest areas, the researchers say that 45,000 more orangutans could be lost over the next 35 years if the situation isn’t addressed.

“Orangutans are flexible and can survive to some extent in a mosaic of forests, plantations, and logged forest, but only when they are not killed,” said Prof Serge Wich of Liverpool John Moores University, who co-authored the paper detailing the research. “So, in addition to protection of forests, we need to focus on addressing the underlying causes of orangutan killing. The latter requires public awareness and education, more effective law enforcement, and also more studies as to why people kill orangutans in the first place.”